Propeller synchronizing and other instruments



Sept. 16, 1941.

PROPELLER SYNCHRONIZING AND OTHER INSTRUMENTS Filed Jan. '2.4, 1941 vv 2Sheets-Sheet 1 v lila/ieri? Paw-'ansi INV ENT OR.

Sept. 16, 1941. W. P. POWERS l 2,256,170

PROPELLER SYNCHRONIZING AND OTHER INSTRUMENTS Filed Jan. 24, 1941 2Sheets-Sheet 2 Walefl Pan/am, INVENTOR.

ATTORNEY M Pl, m 43 .19 M` M BY I Patented Sept. 16, 1941 raorELLEnsYNcnaoNrzmG AND o'rmm msranm'rs walter r. rowers, East orange', N. J.,mimi to Associated latentees, Inc., a corporation of New l JerseyApplication January 24, 19741, serial No. 375,817

' 1 calms. (c1. 11e- 129) The invention here disclosed relates toindieatingy and control devices generally and'while not so restricted,is particularly adapted to such purposes as indicating and, or,controlling synchronization of motors, propellers and the like.

The objects of the invention are `to provide an accurate and sensitiveinstrument of simple, practical design, which will magnify relativelyslight variations or deviations to render them the more readily readableor controlling in effect. A

, Further special objects are to provide an instrument of suchcharacteristics, particularly adapted to multi-engine aircraftforindicatingrelative engine or propeller speeds and for aiding in bringingthe propellers into desired synchronization. l

Other desirable objectsand the novel features of the invention by whichthe objects are at- Y tained will appear and are particularly pointedout in the following specification. f The drawings accompanying andforming part ofthe specification illustrate diilerent practicalembodiments ofthe invention. The actual physical structure however vmaybe modied and changed in many different ways, all within the true intentand broad scope of the invention as will be apparent from the followingspecification and the claims broadly defining the invention.

Fig. 1 is a' front elevation of the invention as,

1 embodied in a four engine propeller synchronizer, illustratingconditions" with the No. 1 engine brought up to speed and the No. 2engine brought and lined in vrnier relation are positioned individuallyaccording to speeds of the other three engines. 4

Details of the speed responsive mechanism are not shown, since ordinarytachometers, revolution counters or the like, may be employed.

Thus in Fig. 3, the elements indicated at Il, l2.'

I3, H, within the case I5, maybe considered as tachometers ydriventhrough shafting I6, I1, il,

is, zronrthe No. 1, No. 2, No. 3 and No. 4 engines Aand operatingrespectively the centrally disposed shaft 2i), carrying the main gridandthe shafts 2|, 22 and 23," grouped about the main lup close tosynchronization, while the No. 3 and No. 4 engines may be simply idling.

Fig. 2 is a similar view, illustrating appearance of the instrument withall four propellers synenronized. l

Fig. 3 is a side elevation of the instrument. broken away at the frontand shown in section to illustrate details of construction. Y

Fig.,4 is a face view of4 another form of the propeller synchronizer. n

Fig. 5 is a broken sectional view as on substantially theplane of line5--5 of Fig. 4.

Fig. 6 is a view showing the first propeller indicator disc with mainindicator grid andthe other three discs with grids to match the nrst ormain. grid. v f

Figs. 7 and 8 are broken, sectional views lof a standard or referencegrid.

In the four engine type of synchronizer shown `in Figs. 1, 2 and 3, amain, parallel line circular grid 1, is positioned by the No. 1 or otherengine usadas thel standard and smaller circular grids 8,

shaft and carrying the three smaller grids 8, 9, I0.

The front of the instrument case is shown closed by a transparent cover,carrying an engine or propeller revolutions scale 25, for the pointer26, of the main grid, at the center and vparallel with the lines of thatgrid. This transparent cover is also shown-as carrying designations 21,28, 29, for the other engines or propellers in positions `associatedwith the grids of those other power devices.

The grids 8, A9, Ill, to be synchronized with the main grid also areshown as having arrows or pointers 30, 3|, I2, centrally disposed andparallel with the lines of such grids.

In ordinary use, the No.v 1 engine, or whichever engine is tol be usedas the standard, is brought. up to speed, as by throttle adjustment orin the case of variable pitch-propeller blades, by adjustment of bladeangle to effect desired loading'of the engine. 'I'his situation isvisualized in Figs. 1 and 2, with the arrow of the main grid pointing tothe top center of the R. P. M. scale. Withy the desired engine .loadingand propeller speed for the No. l or standard power unit effected, thenext -power u'nit such as the No. 2

are of aid in bringing later units up to speed of the iirst unit. As thecritical state of synchronization is approached, the parallel lines ofthe smaller grid, because of their vernier relation to the-lines of thelarger main grid will create the eil'ect of a dark bar or bars 33,having angular movement of much greater extent than the any gularmovement creating the same. Hence the pattern forming the indicator baror bars 33, will swing through a relatively large angle for acomparatively small angular movement. of the grid itself. As aconsequence, the instniment is most i, l0, placed in front of orbehindthe main grid sensitive and becomes the more sensitive as actu-`:lustmemts can therefore be easily made.

ldark pattern bars are easily read and because of son with the mainindicator pointer.

al synchronization is approached. Very ne ad- These their greaterangular movement show up smaller variations than can be detected bycompari- Thus in the case indicated in Fig. 1, the pointer of the secondpropeller grid indicates what appears to `be synchronous relation to therst engine, `whereas the black pattern bars show that the `secondpropeller has not quite. been brought up to actual synchronization.

In Fig. 1, the indicator discs 9 and I0, by their arrows 3 l and 32, andthe out of register relation with the main indicator disc, show the No.3

and No. 4 engines, for instance, to be idling or at rest. k'l'heseengines can be brought up to synchronous speed, in the same way asdescribed with respect to the No. 2 engine, the pointers 3l,

32 aiding in effecting coarse adjustments and the magnied or exaggeratedindications provided bythe vernier bars enabling the liner adjustmentsto be quickly and accurately made.

In the fully synchronized condition oi.' all four engines, theinstrument may appear as in Fig. 2,

with the dark bars or shadow patterns all parallel.

In this particular situation, with the main grid'A at top center on theR. P. M. dial, the lines of the grids and the vernier shadows created bythem all stand vertical, but it will be realized that for otheradjustments or the main grid, that is, angled to one side or the other,the smaller grids and the vernier shadows created by the either directlyin iront or from various angles.

These bars furthermore, are the full extent ci the overlapping portionso! companion grids an'd this factor, together with the wide angle o!travel for comparatively slight grid movements, contributes greatly tothe ease ofreading, accuracy of adjustments and the like.

Means may be provided for making compensating adjustments, if required,to assure the grids coming into registered relation when the powerdevices are fully synchronized.

In cases where it is desired to hold a particular speed, anadditionalstandardizing grid may be placed over the No. 1 grid, lined in vernierrelation to that grid, so as to provide a guide or indicating patternfor that selected speed. Such a standardizing grid, is indicated at 34,Figs. 7 and 8, ncarried by a ring 35, which can be trictionally engagedover the rim or annular shoulder 36. on the iront of the instrument andtherel adjusted to position for the speed which it is tions in'speed inany one of the four engines will instantly show by shiftingof theindicator bar for any such engine.

'I'he instrument may be illuminated in various ways, for instance, by alamp within the instrugrid. Y

With this special arrangement, the indications for all engines may beread in a single row.

In the particular case illustrated in Fig. 4, the single heavy bar atthe left, formed by cooperation of the No. 2 engine, grid-46, with theNo. 1 main grid, shows that the No. 2 propeller'is synchronized with No.1 and the relatively inclined series of bars produced by cooperation oflgrids 41 `and 48, with the main grid 45, show that the v No. 3 and No. 4propellers are below speed, the

No. 3 to a greater extent than No. 4. f

Instead of being simply utilized as a pointer for indicating purposes,the solid black bar produced by cooperation of the vernier grids may beused for control purposes, such as to cut oif or vary a beam ofV light.and the like. The invention and various features ci the invention areapplicable to many other purposes than the one illustrated and are to beso understood.

In selecting and arranging the cooperating grids, the one oi nner pitch,that is, with the closer spacing oi.' lines or bars should be connectedwith the moving part if itis intended that the pattern or indicating barshall travel in the same direction of movement. Conversely, reversetravel of the indicator pattern can be effected by connecting thecoarser pitch grid with the moving part.

`. In using a standardizing grid such as indicated at 34, Figs. 7 and 8,it may be considered most desirable to have such grid of a size to coveronly a portion oi the No. 1 grid, such as that part at the top in Fig.2, between the side grids 8 and l0, so that such standardizing grid willbe cooperative only with the main grid and will have no effect on orcooperation with the other grids.

What is claimed is:

1.l In an instrument of the character disclosed,

the combination of superposed main and supplemental grids composed ofparallel lines in `Vernier relation to cooperatively produce a shadowbar extending across the eld of 'overlap of the superposed grids, saidgrids being mounted for relative rotational adjustments of one inrespect to the other, there being a plurality of said suppledesired tomaintain. Any variation from such speed will then show up at once byangular shifting movement of the indicator bar created by proximity ofthis standardizing grid over the No. 1 grid. This superposed referencegrid, it as large as the No. 1 grid, cooperates with the latter to formindicator bars extending continuously the way across the No. 1 grid,`and these may cooperate with the indicator bars produced throughcooperation of the No. 1 with the No. 2,- 3 and 4 grids, to reinforceand accentuate the latter.

With this superposed reference grid, any variamental grids in superposedrelation to said main grid and each being rotationally adjustableindependently of said main grid, said main grid being `of a width tocollectively cooperate with all the supplemental grids, the latterindividually being of less width and positioned'to stand inA a singlerow when main grid.

2. In an instrument of the character disclosed, the combination ofsuperposed main and supplemental grids composed of parallel lines invernier relation to cooperatively produce a shadow bar extending acrossthe eld of overlap ofthe super.

cooperatively related to said posed grids, said grids being mounted forrelative rotational adjustmentsl of one in respect to the other, astandard grid in adjustable superposed relation to said main grid, saidmain grid being of larger size than the supplemental grid and saidstandard grid being of a size and position to cooperate only with thatportion of the larger main grid not covered by the supplemental grid andnot .to cooperate withA the smallersupplemental grid.

3. A multiple engine propeller synchronizer, comprising a. fiat maingrid of spaced substantially parallel lines mounted for pivotal movementon an axis substantially at right angles to the plane of said grid, anengine driven speed responsive device for rotationally positioning saidmain grid, other individual engine speed responsive fiat grids pivotallymounted in overlying substantially parallel relation to said main gridand composed of spaced substantially parallel lines in vernier relationto the lines of said main grid to cooperatively form with said main gridindicator bars extending the full extent of superposition of said otherand main grid lines and engine speed responsive devices for individuallyrotationally positioning said other grids in respect to said main grid.

4. A multiple engine propeller synchronizer,

comprising a fiat main grid of spaced substantially parallel linesmounted for'pivotal movement on an axis .substantially at right anglesto the plane of said grid; an engine driven speed responsive device forrotationally positioning said maingrid, other` individual engine speedresponsive flat grids pivotally mounted in overlying substantiallyparallel relation to said main grid and composed of spaced substantiallyparallel lines in Vernier relation to the lines of said main grid tocooperatively form withsaid main grid indicator bars extending the fullextent of superposition of said other and main grid lines andenandcomposed of spaced substantially parallel lines in vernier relationto the lines of said main grid to cooperatively form with said main gridindicator bars extending the full extent oi superposition of said otherand main grid lines and engine speed responsive devices forindividuallyrotationally positioning said other grids in respect to said main grid,the pivotal axes of said other grids being disposed about and insubstantially parallel relation with the pivotal axes of said main grid.

6. A multiple 4engine propeller' synchronizer, comprising a fiat maingrid of spaced substantially parallel lines mounted for pivotal movementon an axis substantially at right angles to the plane of said grid, anengine driven speedresponsive device for rotationally positioning saidmain grid, other individual engine speed responsive ilat grids pivotallymounted in overlying substantially parallel relation to said main grid-and composed of spaced substantially parallel lines in Vernier relationto the lines of said main gine speed responsive devices for individuallyrotation'ally positioning said other grids in respect to said main grid,said other grids being smaller than said main grid and arranged clear ofeach other and in overlying relation only to said main grid.

5. A multiple engine propeller synchronizer, comprising a ilat main gridof spaced substantially parallel lines mounted for pivotal movement onan axis substantially at right angles to the planeof said grid, anengine driven speed responsive device for rotationally positioning saidmain grid, other individual engine speed responsive flat grids pivotallymounted in overlying substantially parallel relation to said main gridgrid to cooperatively form with said main grid indicator bars extendingthe full extent of superposition of said other and main grid lines andengine speed responsive devices for individually rotationallypositioning said other grids in respect to said main grid, said main andsaid cooperating other grids being all concentrically mounted on thesame pivotal axis.

"7. A multiple engine propeller synchronizer, comprising a fiat maingrid of spaced substantially parallel lines mounted for pivotal movementon an axis substantially at right angles to the plane of said grid, anengine driven speed responsive device for rotationallypositioning saidmain grid, other individual engine speed responsive flat grids pivotallymounted in overlying substantially parallel relation to said main gridand composed of spaced substantially parallel lines in vernier relationto the lines of said main grid to cooperatively form with said main gridindi- A 'cator bars extending the full extent oi superposition of saidother and main grid lines, engine speed responsive devices forindividually rotationally positioning said other grids in respect ntosaid main'grid and a standard grid of spaced substantially parallellines in'vernier relation over said main grid and adjustableangularlyabout the same axis as said main grid to positions of differentengine speeds and cooperative with said main grid to form heavyindicating bars extending across the combined eld of said'main andstandard grids to show when said main grid is at desired engine speedindicating position `WALTER P. POWERS.

